till 1?REACE, 



The common names of difeafes are not well adapted 

 to any kind of claffification, and leaf! of all to this, from 

 their proximate caufes. Some of their names in com* 

 mon language are taken from the remote caufe, as 

 worms, (tone of the bladder ; others from the remote 

 efFefi:, as diarrhoe^ falivation, hydrocephalus 5 others 

 from fome accidental fymptom of the difeafe, as tooth- 

 ach> head-ach, heart-burn ; in which the pain is only a 

 concomitant circumftance of the excefs or deficiency of 

 fibrous aftionSj and not the caufe of them. Others 

 again are taken from the deformity occafioned in confe- 

 ijuence of the unnatural fibrous motions, which confti- 

 tute difeafes, as tumours, eruptions, extenuations ; all 

 thefe therefore improperly give names to difeafes ; and 

 fome difficulty i thus occafioned to the reader in en* 

 deavouring to difcover to what clafs fuch diforders 

 belong* 



Another difSculty attending the harries of difeafes is : < 

 that one name frequently includes more tlian one difeafe^ 

 either exiftlng at the fame time or in fucceflion. Thus 

 the pain of the bowels from worms is caufed by the in 

 creafed action of the membrane from the flimulus of 

 thofe animals k > but the convulfionSj which fometimes fuc- 

 ^ceed thefe pains in children, are caufed by the confequent 

 Volition, and belong to another clafs; 



To difcover under what clafs any difeafe fliould be ar- 

 ranged, we mud firft invefligate the proximate caufe 5 

 thus the pain of the tooth-ach is not the caufe of any 

 difeafed motions, but the eiteft ; the tooth-ach there- 

 fore 



